In the present document, this assembly of two male-female elements is called a “connector”. It is normal, notably in the automotive industry, to use such clip-on connectors to produce the quick and demountable connection of an element of a fluid (for example fuel, oil or water) circuit to another circuit element. Virtually standardized in the industry is the use of male end fittings including a cylindrical bush surrounded by a flange and the female connectors include a cylindrical cavity adapted to receive at least the end of the bush and an elastic latch adapted to lock onto the back of the flange once the latter is in place. O-rings provide the seal around the male end fitting.
The document EP 0 605 801 discloses a connector in which the latch is symmetrical and disposed transversely in a latch housing formed between the opening of the cylindrical cavity of the body and a rigid entry ring of the body placed at a distance in front of the opening of the cylindrical cavity of the body and fastened to the body. The oval or lozenge-shaped latch part is elastically deformable and includes two actuating members at two opposite apex and two jaws at two other apex. In the rest position, the actuating members are flush with the external envelope of the body and accessible to two opposed fingers of a user. When the user presses these parts radially inwards, the latch part is deformed and moves the two jaws laterally away from each other and away from the axis of the body so that the jaws are retracted and release the adjacent central region of the periphery of the male end fitting and allow disengagement of the flange and therefore of the male end fitting.
The single lozenge-shaped latch part proves relatively fragile in use. To enable its elastic operation, it is necessary to provide connecting parts that are not too thick or too rigid and because of this the jaws may be retained insufficiently and not exert sufficient force on the flange of an end fitting to prevent pulling out of the end fitting.